(a) Field of the Invention
The present invention relates to a tool used when servicing a motor vehicle disc brake device, and more particularly to a measuring tool for disc brake device brake pad, wherein the measuring tool in question is used to measure the distance between the brake pad and the brake disc.
(b) Description of the Prior Art
A motor vehicle disc brake device is mounted on the wheel axle of a motor vehicle so as to be adjacent to the wheel, and the disc brake device is used to cause the motor vehicle to slow down and brake.
The disc brake device primarily uses a pair of mutually corresponding brake pads respectively mounted on the two sides of a brake disc. The brake disc is connected to the wheel axle of the motor vehicle and rotates in synchronicity with the wheel axle. Each of the brake pads is adjacent to the respective surface of the brake disc, and is provided with a friction block. When each of the brake pads clamps the respective surface of the brake disc, each of the friction blocks contacts the respective side surface of the brake disc. The corresponding friction between each of the friction blocks and the brake disc is used to reduce the rotational speed of the wheel axle, thereby achieving the objective of slowing down and braking the motor vehicle. However, the contact friction between the friction blocks and the brake disc causes wear and tear of the friction blocks, resulting in a gradual decrease in the thickness of the friction blocks. When the thickness of the friction blocks has decreased to being equal to or less than a preset safety value, then neglecting to replace the brake pads will bring about a reduction in the effectiveness of slowing down and braking the vehicle, and thereby endangering driving safety.
The distance between the mutually adjacent surfaces of the brake pads and the brake disc can serve as a basis to determine the thickness of the friction blocks, and accordingly decide whether or not to replace the brake pads.
To measure the distance between the brake pads and the brake disc, the wheel needs to be detached from the wheel axle to expose the disc brake device, then a thickness/gap gauge is used to measure the distance between the brake pads and the brake disc. Hence, such a measuring method requires detaching the wheel, which is time consuming and complicated.